"He detonated his fine, astonishing and well-designed explosive device, which was unseen by the eyes of those who do not believe in the hereafter," said Mustafa Abu al-Yazid, al Qaeda's number three, according to a translation by the SITE Intelligence Group.

Yazid claimed al Qaeda launched the attack as payback for the deaths of three militant leaders: Baitullah Mehsud, the former head of the Pakistani Taliban; Saleh al-Somali, who was in charge of al Qaeda operations outside of Pakistan and Afghanistan; and Abdullah Saeed al-Libi, a senior Libyan member of the group.

All three were killed by the increasingly effective drone campaign in Pakistan's tribal areas. The campaign is run by the CIA, and U.S. officials say drone strikes have killed a dozen senior militant leaders on a constantly refreshed list of 20 top terrorist targets.

Was CIA Bombing Payback for Attack on Haqqani Group?

The drone strikes "have been very effective, and they have knocked al Qaeda and other Islamic extremist organizations off balance," Sen. John McCain, the ranking member of the Senate Homeland Security and Governmental Affairs committee, told reporters today in Kabul. The strikes "can claim measurable success in having carried out those operations, and I think that they should continue."

Previously, both the Afghan Taliban and the Pakistani Taliban have claimed credit for the attack, and U.S. officials say it's still not clear whom Hamam Khalil, whose last name is often written as al-Balawi, was working with.

Residents on both sides of the Afghan-Pakistani border where the CIA base was attacked say nothing happens in the area without the knowledge of the Haqqani group, one of the most lethal Taliban organizations.

U.S. officials acknowledge that al-Balawi could have been working with senior Haqqani militants, and it's those Haqqani leaders who have been struck by drone strikes nearly every day since the CIA base was attacked Dec. 30. Just yesterday two drone strikes hit the same target in North Waziristan, just over the border from where the CIA base was attacked.

Wednesday's dual strikes targeted militants living in the house and then the people who were cleaning up the house's remains, according to residents and regional intelligence officials. It appears to be one of the first times in the five year drone campaign that a missile targeted a group picking through the rubble of an earlier drone strike. A total of 12 people died in the twin strikes.

United States officials admit drone strikes are the most effective means they have to attack the senior leadership of al Qaeda and the Haqqani network, both of which operate out of North Waziristan. The United States has asked the Pakistani government and military to expand an operation against the Pakistani Taliban to the Haqqani network, but they have declined, according to Western officials. The Pakistani military argues it would be overstretched if it went after al Qaeda and Haqqani militants in North Waziristan.

In response, U.S. officials have publicly threatened to increase the number of drone strikes across the region. They seem to have followed through with that threat, especially since the CIA base was attacked on Dec. 30. In the last six days, North Waziristan has been hit with one of the largest number of strikes to occur in a single week since the drone campaign began.

The CIA launched more than 50 drone attacks in 2009, compared to more than 30 in 2008, according to an ABC News tally. The CIA officials based at Camp Chapman were at the center of the drone campaign, according to intelligence officials, and they were looking for informants to help them find senior al Qaeda and Haqqani leaders.

Are Al Qaeda and Taliban Coming Together?

It's not clear whether the three claims of responsibility are evidence that al Qaeda, the Afghan Taliban, and the Pakistani Taliban are working distinctly from each other or they have launched a coordinated information campaign.

A NATO intelligence officer recently told reporters in Kabul that the Afghan Taliban, Pakistani Taliban, and al Qaeda are "coming into alignment."

"May God accept [al-Balawi] as a martyr who was able to infiltrate the Americans' forts," al-Yazid said in the statement. "We ask God to bless the people who follow your path, Abu Dujana," a reference to the screen name al-Balawi used on jihadist Web sites.

"Let them know that your brothers are following your path and they will not have peace of mind until they slaughter the Americans and let the Islamic nation be proud for having men like you among its sons."